Water pump for vehicle

ABSTRACT

The present disclosure provides a water pump for a vehicle including an impeller with an impeller discharging port configured to pump and discharge coolant, a shroud movably installed to open and close the impeller discharging port, a first pushing unit configured to push the shroud in a direction of opening the impeller discharging port, and a second pushing unit configured to push the shroud in a direction of closing the impeller discharging port.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of U.S. Non-Provisional application Ser. No. 16/124,678 filed Sep. 7, 2018, which claims priority to and the benefit of Korean Patent Application No. 10-2017-0174098 filed on Dec. 18, 2017, the entirety of each of these applications is hereby incorporated by reference.

FIELD

The present disclosure relates to a water pump for a vehicle, and more particularly, a water pump for a vehicle capable of controlling a discharge flow rate in multiple stages.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Generally, a water pump used in a vehicle is a device for improving the cooling efficiency of the engine by forcibly circulating the coolant of the engine. It may be divided into a mechanical water pump which directly receives rotational drive power from the engine to be driven in proportion to the number of revolutions of the engine and a variable or electric water pump which is operated through a separate drive source such as a motor without directly receiving rotational power from the engine.

Since the mechanical water pump is disadvantageous in terms of energy efficiency and fuel efficiency because it cannot control variously the driving mode of the water pump in accordance with the driving state of the engine and the vehicle, the variable water pumps have been recently applied to improve fuel efficiency, and so on, even at the expense of rising costs.

Various methods have been used to control the discharge flow rate of variable water pump to various discharge modes.

For example, a vacuum type water pump is a structure that adjusts the impeller outlet by operating the slide with a negative pressure. It is advantageous in terms of layout and has a simple control structure.

The water pump of the intermediate wheel type is a structure that controls the rotation of the pulley by moving the position of the intermediate wheel through a built-in actuator, which is disadvantageous to durability due to slip and abrasion, and or the like.

Furthermore, an electronic clutch type water pump, which controls the rotation of the impeller through an incorporated clutch, is advantageous in terms of layout but has a complicated drawback, and a variable water pump, which controls the speed of the pump by controlling the connection or disconnection of a pulley and a drive shaft through permanent magnet, has been usually applied to commercial vehicle, but it is difficult to precisely control the intensity of permanent magnet and since the slip in the magnetic field requires radiating fins, which makes the structure thereof complicate and disadvantage in terms of cost.

SUMMARY

The present disclosure provides a water pump for a vehicle capable of reducing the weight and cost by simple structure and precisely controlling the flow rate discharged from the water pump in multiple steps.

A water pump for a vehicle in one form of the present disclosure may include, an impeller with an impeller discharging port pumping and discharging coolant, a shroud movably installed to open and close the impeller discharging port, a first pushing unit configured to push the shroud in a direction of opening the impeller discharging port, and a second pushing unit configured to push the shroud in a direction of closing the impeller discharging port.

A drive shaft may be installed at the impeller and a pulley may be connected with the drive shaft.

The shroud may be movably installed in the axial direction along the drive shaft.

The first pushing means may include a spring disposed between the impeller and the shroud.

The second pushing unit may include a wax being connected with the shroud through a pushrod and volume-expanding or contracting depending on the supplied heat amount, and a heater selectively supplying heat to a wax.

The heater may be connected to the engine control unit to be controlled by the operating signal of the engine control unit.

The engine control unit may be to apply an operating signal to the heater so that the heater heats up to the wax when the engine warms up.

The engine control unit may apply an operating signal to the heater corresponding to the rotation speed of the engine, the load, and the ambient temperature.

In accordance with a water pump for a vehicle in another form of the present disclosure, the heater is operated according to the control signal of the engine control unit to control the amount of heat supplied to the wax, so that the opening of the impeller outlet through the shroud supported by the spring and the discharge flow rate of the water pump can be precisely controlled in a stepwise manner.

By controlling the shroud to adjust the impeller outlet through only the wax and heater, the control structure can be simplified and weight and cost can be saved, and durability can be improved because there is no friction element.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is an example of a coolant circulation system for a vehicle to which a water pump is applied;

FIG. 2 is an operating cross-sectional view when the water pump for the vehicle does not discharge the flow rate;

FIG. 3 is an operating cross-sectional view when the water pump for the vehicle discharges the flow rate; and

FIG. 4 is an operating cross-sectional view when the water pump for the vehicle discharges the maximum flow rate.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

While the disclosure will be described in conjunction with exemplary forms, it will be understood that present description is not intended to limit the disclosure to those exemplary forms. On the contrary, the disclosure is intended to cover not only the exemplary forms, but also various alternatives, modifications, equivalents and other exemplary forms, which may be included within the spirit and scope of the disclosure as defined by the appended claims. The terminology used herein is for the purpose of describing particular forms only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, in order to make the description of the present disclosure clear, unrelated parts are not shown and, the thicknesses of layers and regions are exaggerated for clarity. Further, when it is stated that a layer is “on” another layer or substrate, the layer may be directly on another layer or substrate or a third layer may be disposed there between. It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicle in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats, ships, aircraft, and the like and includes hybrid vehicles, electric vehicles, combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). Some forms of the present disclosure will now be described in detail with reference to the accompanying drawing. Referring to FIG. 1, an engine coolant circulation system for a vehicle to which a water pump for a vehicle in some forms of the present disclosure is applied may be configured as follows.

A water pump for a vehicle 1 in some forms of the present disclosure pressurizes and pumps coolant to supply it to a cylinder block 2 of an engine; the coolant cools a cylinder block 2 and a cylinder head 3 and then, discharged from the cylinder head 3 to be flowed into a direction adjusting valve 4.

Some coolant flowed into the direction adjusting valve 4 is heated by a heater 6 via a low pressure EGR (Exhaust Gas Recirculation) cooler 5, and then flows into the water pump 1 and some coolant flowed back to the water pump 1 via an EGR valve 7.

Some coolant flowed into the direction adjusting valve 4 is injected into a reservoir tank 8 and stored in the reservoir tank 8 or supplied to a radiator 9 to be cooled and then flows into a thermostat valve 10, and the coolant passing through the thermostat valve 10 is again flowed into the water pump 1.

Furthermore, some coolant flowed into the direction adjusting valve 4 is flowed into the water pump 1 via an ATF warmer 11, an oil cooler 12 and a high pressure EGR cooler 13, and the coolant discharged from the reservoir tank 8 flows into the thermostat valve 10.

The water pump 1 in some forms of the present disclosure applied to the coolant circulation system as described above may include, as shown in FIG. 3, an impeller 32 for pressurizing and pumping the coolant supplied from an inlet 30 to a pumping chamber 29 and discharging through an impeller discharging port 31, a drive shaft 33 thereof, and a pulley 34 for supplying rotational power to the impeller drive shaft 33.

A bearing 35 may be mounted at the outer circumference of the impeller drive shaft 33 to support the impeller drive shaft 33 to be rotatable.

The impeller discharge port 31 may be closed or partially open or fully open by a shroud 36 which may be movably mounted along the impeller drive shaft 33. In some forms of the present disclosure, the impeller discharging port 31 is formed to a pump housing (not shown) and the shroud 36 may close and open the impeller discharging port 31.

A spring 37 may be installed as a first pushing means between the impeller 32 and the shroud 36 to elastically push the shroud 36 in a direction to open the impeller discharging port 31. The spring 37 may be seated on and supported by a spring seat 38.

A second pushing means may be provided opposite the spring 37 to push the shroud 36 in a direction closing the impeller discharging port 31.

The second pushing means may include a wax 40 that volumetrically expands or contracts according to the calorie supplied with the shroud 36 via a pushrod 39 and a heater 41 that does not supply or supply heat to the wax 40.

The heater 41 may be connected to an engine control unit ECU, and its operation may be controlled according to the control signal of the engine control unit ECU.

The heater 41 and the wax 34 may be connected to a heat conducting wire 42 or a heat conducting rod.

The engine control unit The ECU can judge the driving state of the engine and also judge the driving state of the vehicle through various sensors.

The operation state of FIG. 2 shows the state that the engine control unit ECU applies an operation signal to the heater 41, and the heat generated in the heater 41 is supplied to the wax 34 through the heat conducting wire 42, so that the wax 34 is expanded to the maximum, the spring 37 is compressed by the shroud 36.

The pushrod 39 pushes the shroud 36 according to the volume expansion of the wax 34, as shown by the arrows, so that the shroud 36 closes the impeller discharging port 31 to prevent the circulation of the coolant through the water pump 1 and the coolant temperature rises quickly, thereby shortening the warm-up time of the engine and improving fuel efficiency.

When the coolant temperature rises appropriately after the warm-up of the engine, the engine control unit ECU controls the operating signal of the heater 41 to control the amount of heat generated by the heater.

Then, as shown in FIG. 3, the position of the shroud 36 is adjusted at the point where the elastic restoring force of the spring 37 and the expansion force of the wax 40 are in equilibrium, the impeller discharging port 31 is opened to the partial by the shroud 36, and the coolant circulation is performed while the water pump 1 pressurizes and discharges the coolant.

The engine control unit ECU can control the heat amount generated by the heater 41 by controlling the operation signal applied to the heater 41 according to the predetermined map or the program in consideration of the factors such as the rotation speed of the engine, the load and the outside temperature. For example, in the high load operating range of the engine, the coolant discharge flow rate is increased and in the low load operating range of the engine, the discharge flow rate is reduced to improve the fuel efficiency.

On the other hand, when the coolant temperature of the engine rises to become hot, the engine control unit ECU interrupts the operating signal applied to the heater 41, and accordingly the shroud 36 is pushed in the direction of opening the impeller discharging port 31 to fully open the impeller discharging port 31, so that the coolant circulates rapidly along the circulating system.

In some forms of the present disclosure, although the spring are exemplified as the first pushing means and the wax and the heater as the second pushing means, a solenoid valve, a clutch or the like can be replaced.

The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.

DESCRIPTION OF SYMBOLS

-   1: water pump -   2: cylinder block -   3: cylinder head -   4: direction adjusting valve -   5: low pressure EGR cooler -   6: heater -   7: EGR valve -   8: reservoir tank -   9: radiator -   10: thermostat valve -   11: ATF warmer -   12: oil cooler -   13: high pressure EGR cooler -   29: pumping chamber -   30: inlet -   31: impeller discharging outlet -   32: impeller -   33: drive shaft -   34: pulley -   35: bearing -   36: shroud -   37: spring -   38: spring seat -   39: pushrod -   40: wax -   41: heater 

What is claimed is:
 1. A water pump for a vehicle, comprising: an impeller with an impeller discharging port that is configured to pump and to discharge coolant; a shroud movably installed and configured to open and to close the impeller discharging port; a first pushing unit configured to push the shroud in a direction of opening the impeller discharging port; and a second pushing unit configured to push the shroud in a direction of closing the impeller discharging port.
 2. The water pump for the vehicle of claim 1, wherein: a drive shaft is provided in the impeller; and a pulley is connected with the drive shaft.
 3. The water pump for the vehicle of claim 2, wherein the shroud is movably installed in an axial direction along the drive shaft.
 4. The water pump for the vehicle of claim 1, wherein the first pushing unit comprises a spring disposed between the impeller and the shroud.
 5. The water pump for the vehicle of claim 1, wherein the second pushing device comprises: a wax connected with the shroud through a pushrod, the wax configured to expand or contract depending on a heat amount; and a heater selectively configured to supply heat to the wax.
 6. The water pump for the vehicle of claim 5, wherein the heater is connected to an engine control unit and controlled by an operating signal of the engine control unit.
 7. The water pump for the vehicle of claim 6, wherein the engine control unit is configured to apply the operating signal to the heater such that the heater heats up the wax when an engine warms up.
 8. The water pump for the vehicle of claim 6, wherein the engine control unit is configured to apply the operating signal to the heater corresponding to a rotation speed of the engine, a load, and an ambient temperature. 